Field of the Invention
The present invention is referred to a system for cutting and separating in individual doses the medicaments usually packed in a blister pack. The invention is, however, more particularly directed to a system to be used by hospital pharmacies, nursing homes, drug distribution centers, etc. to individually cut, separate, pack and identify drugs.
Background of the Invention
A blister pack is a type of packaging in which a product is sealed in plastic, often with a cardboard backing. Blister pack is a term for several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals.
The main component of a blister pack is a cavity or pocket made from a formable thermoformed plastic. This usually has a backing of paperboard or a lidding seal of aluminum foil or plastic. A blister pack that folds onto itself is often called a clamshell.
Blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges. Blister packs can provide barrier protection for shelf life requirements, and a degree of tamper resistance. In the USA, blister packs are mainly used for packing physician samples of drug products, or for over the counter (OTC) products in the pharmacy. A series of blister cavities is sometimes called a blister card or blister strip as well as a blister pack. These types of packaging have two key properties:                (i) the lidding foil is brittle; allowing to press the product out while breaking the lidding foil and;        (ii) a semi-rigid formed cavity being sufficiently collapsible to be able to dispense the tablet or capsule by means of pressing it out with the thumb.        
The main advantages of unit-dose blister packs over other methods of packing pharmaceutical products are the assurance of product/packaging integrity (including shelf life) of each individual dose and the possibility to create a compliance pack or calendar pack by printing the days of the week above each dose.
Blister packs are created by means of a form-fill-seal process at the pharmaceutical company or designated contract packer. A form-fill-seal process means that the blister pack is created from rolls of a flat sheet or film filled with the pharmaceutical product and closed (sealed) on the same equipment. Such equipment is called a blister line. The forming film is typically made of a thermoplastic material, such as polyvinyl chloride (PVC), Polyvinylidene chloride-coated PVC (PVDC), PET or aluminum foil.
The lidding material can be clear plastic, but in pharmaceutical packaging it is either plain or printed foil. Aluminum foil is most commonly the preferred material. The lidding material may also be made of a laminate of paper and foil with the foil upper surface being coated with a film of a thermoplastic material such as polyethylene or polystyrene.
Blister packs are opened, providing access to the medicament by deforming the forming film so that it punctures the lidding material and allows the medicament to be removed therefrom, without applying directly mechanical pressure to the medicament.
Hospital pharmacies usually receive blister-packed medicines. However, in a hospital, medicines are to be dispensed in the correct dose to be taken by the patient. In pharmacies, a “de-blistering” operation is therefore necessary; consisting of removing the units of medicine that are required from the blister pack, by breaking the sealing sheet, so as to put them in an intermediate container (glass, bottle) in which the medicine or medicines to be administered are taken to the patient.
A problem associated with this de-blistering process is that, although it is easy to perform by using de-blistering machines of a known type, the units of medicine may be damaged, lost or stolen during the transfer to the patient in the hospital.
Therefore, hospitals are trying to avoid this process and, instead of de-blistering the pills, they usually separate the pills individually. Pharmacies at hospitals convert these blister packs into units and identify each drug with new codes and/or names to be delivered to nurses.
Every time the hospital needs to provide a pill to a patient, the pharmacy needs to separate one pill from the blister pack. However, this separation process cannot take place by taking out the pill from the cavity, as the medicament may be contaminated or deteriorated. Therefore, the whole cavities with the pill inside need to be separated from the blister pack, usually by cutting then out with a pair of scissors. In order to cut the blister pack, the process is done manually. This process of separating individual cavities with a pair of scissors is called a “unitization dose” process.
One of the main challenges for creating a machine to separate the doses in units is because of the shape and distribution of the pills in the blister packs. In some cases, the pills are arranged in perfectly aligned pairs, in some cases the distribution defines a zigzag arrangement of the cavities with the pills, in some cases the distribution is circular, etc. The machine with scissors cannot cut other than “line cuts” so when the pills are arranged in zigzag the machine cannot cut them.